Marital disruption disproportionately affects low-income black couples. To understand the unique experiences of black families, ethnographic research suggests that the lives of black couples are affected not only by structural elements of their environments, but by the social networks within which couples are embedded. Yet to date there has been no research directly examining the social networks of low-income couples, despite repeated suggestions that these networks should play an especially important role in the lives of black families in low-income communities. The overarching goal of the proposed research is to address this oversight through a four- wave longitudinal study of 150 black and 150 white low-income newlywed couples across the first three years of their marriage. A social network interview, administered at each assessment, will be combined with self-reports of personal history, marital quality, and experiences of stress and discrimination, and census data on neighborhood characteristics, videotaped observations of marital interactions, and interviewer ratings of the home environment. These data will be used to: 1) Describe and compare the social networks of low-income white and black newlywed couples; 2) Describe change in the social networks of black and white newlyweds over the first years of marriage; 3) Evaluate the associations between social network characteristics and marital outcomes. In particular, the proposed research will evaluate the support for three distinct models of how social networks may affect the development of marriages. The Support Model emphasizes how the composition and structure of a couple's social network shapes the transfer of social support between network members and the couple. The Constraint Model suggests that the structure of spouses' shared networks can operate as a constraint on leaving the relationship, and can reduce each partner's exposure to potential alternative relationships. The Social Norms Model addresses ways that the presence of married couples in a couple's network conveys expectations for marriage. The proposed research would be the first to evaluate and compare the support for each of these models, the first to describe the composition and structure of social networks in this population, the first to directly compare the networks of black and white couples of comparable income, and the first to link social network characteristics to observational data on marital interactions and longitudinal data on marital outcomes. Together, the results of the proposed research will inform future directions for programs and policies aimed at improving the lives of low-income couples and reducing racial disparities in marital outcomes within low- income communities.